ICP-AES测定石灰石中氧化镁、三氧化二铁、三氧化二铝

Determination of magnesium oxide,iron oxide and aluminum oxide in limestone by ICP-AES

针对石灰石中某些氧化物杂质难溶、杂质含量高的特点,研究了不同酸溶法和碱熔法对样品的溶解情况,并通过与国家标准方法对比,建立了以HNO_(3)、HCl、HF、HClO_(4) 4种混合酸分解样品,10%的王水作为复溶酸,电感耦合等离子体发射光谱仪测定石灰石中MgO、Fe_(2)O_(3)、Al_(2)O_(3)的方法。选择Mg 202.582nm、Fe 240.488nm、Al 394.401nm为分析谱线,在仪器最佳工作条件下,各氧化物的标准曲线相关系数不小于0.9999,实际样品测定结果的相对标准偏差(RSD,n=7)在0.47%~3.20%之间,各氧化物的加标回收率在95.00%~103.6%之间,标准物质的测定结果满意。该方法流程短,操作简便、快速,精密度高,结果准确、可靠,可以满足石灰石中MgO、Fe_(2)O_(3)、Al_(2)O_(3)的测定。

In view of the characteristics that some oxide impurities in limestone are difficult to dissolve and have high impurity content,the dissolution of samples by different acid dissolution methods and alkali melting methods were studied,and through comparison with the national standard methods,a method was established to decompose the samples with four mixed acids of nitric,hydrochloric,hydrofluoric and perchloric acids,with 10%aqua riga as the re-solubilizing acid,and to determine magnesium oxide,iron oxide and aluminum oxide.Mg 202.582nm,Fe 240.488nm and Al 394.401nm were selected as the analytical lines.Under the best operating conditions of the instrument,the correlation coefficient of the standard curve of each oxygen specific substance was not less than 0.9999,the relative standard deviation(RSD,n=7)of the actual sample determination results were in the range of 0.47%~3.20%,the standard addition recovery of each oxide were in the range of 95.00%~103.6%,and the determination results of the standard substance were satisfactory.The method has the advantages of short flow,simple operation,high precision,accurate and reliable results,and can meet the requirements for the determination of magnesium oxide,iron oxide and aluminum oxide in limestone.